In a wireless communications system, receiving and sending of data at a specific logical location is referred to as a multiple-access manner, and specific logical locations are categorized according to time, a frequency, or a spreading code word. The system implements communication between a base station and multiple user equipments in a multiple-access manner.
In the conventional art, a communications system implements communication between a base station and user equipment in one multiple-access manner. For example, in a communications system that uses an OFDMA (Orthogonal Frequency Division Multiple Access) multiple-access manner, a base station sends downlink data to different user equipments by using different subcarriers, and the user equipments send uplink data to the base station by using the corresponding subcarriers. Because the base station and the different user equipments perform communication by using subcarriers orthogonal to each other, in the communications system using the OFDMA multiple-access manner, the different user equipments do not interfere with each other, and therefore, strong interference immunity is available.
During a process of implementing the present invention, the inventor finds that the conventional art has at least the following problems: Because in a communications system, one multiple-access manner is used throughout to implement communication between a base station and user equipments, disadvantages of the used multiple-access manner accompany with advantages of the multiple-access manner. In a future M2M (machine to machine) service, requirements of different types need to be met in a same network. For example, in a communications system, there may be user equipment in an environment such as a basement or a mine, and therefore, it is required that the communications system have strong coverage, and the requirement of the communications system can be met in an OFDMA multiple-access manner. However, for user equipment that requires high rate transmission or needs to transmit a large amount of small data in the communications system, the requirement cannot be met in an OFDMA multiple-access manner.